Nowadays the usage of wireless sensor networks, with either static or mobile nodes, has been an area of growing interest. From the simplest applications of monitoring, i.e. environmental parameters, to the most complex search and rescue applications, the localization of the various nodes of the network is fundamental. In the situation at which the network has mobility there is additionally a need of the ability to efficiently navigate.
Due to the fact that in many of the applications, i.e. search and rescue situations where the time of action is critical, is impossible to perform a previous planning and building of a framework, anchor free relative localization methods become indispensable.
In this dissertation several relative localization and navigation techniques, based only on the RF signal of the wireless communications, are studied. On the subject of localization, different parameters related with the communications were tested. These are significant because of the necessity of studying the impact of such factors in calculating the network topology. On the subject of navigation the resulting work was experimentally evaluated, with emphasis on the comparative evaluation of the several methods presented in this dissertation, namely a simple oblivious method based on random directions and another one based on MLE - Maximum Likelihood Estimator. The results show the superiority of MLE concerning the speed of getting to the target at the cost of extra computations. In particular, in the scope of this dissertation we have made a small autonomous robot move between to RF beacons, using RSS information, only.